Speed responsive apparatus



Sept. 20, 1938. BONE 2,130,453

SPEED RESPONSIVE APPARATUS Original Filed May 17, 1955 Roiazed from dm'uzhy m emb e1 Slowpelease Slow Z'Ck-u 3 R JD TF -a- F 1 7w L INVENTOR Herbep Liione.

HIS ATTORN EY Patented Sept. 20, 1938 UNITEDJSTATESL'PATENTi-OZFFIEE SPEED RESPONSIVE APPARATUS Herbert L Bone, Forest Hills, Pa. ,*assignor to The .Union Switch & Signal .Company, Swissvale, Pa., a corporation of Pennsylvania Original application May 17, 1935, Serial No.

--; ..22,029. 1 Divided and this application-April 2,

' 1937, Serial N0. 134,634

6 Claims.

My invention relates to speed responsive apparatus.

An object of my invention is the provision of novel and improvedspeed responsive apparatus which is actuated by electrical means, and by which an unsafe indication due to loss of power or breakage of .a part is avoided.

Speed responsive apparatus embodying my invention is particularly suitable for, although in no way limited to, use in connection with speed control systems for railway trains.

This application is a division of my copending application filed May 17, 1935, Serial No. 22,029, now Patent No. 2,103,706, Dec. 28, 1937, for Speed responsive apparatus.

I will describe one form of apparatus embodying my invention, and-will then point out the novel features thereof in claims.

The accompanying drawing is a diagrammatic view-illustrating one form of apparatus embodying my invention.

Speed responsive apparatus embodying my invention embraces a suitable speed responsive circuit interrupting means and a time limit electromagnetic means adapted to come intoaction a short period after the conditions actuating it have begun to exist.- As shown in the drawing, the circuit interrupting means is a commutator, designated as a whole by the reference character Cl, and the time limit electromagnetic means consists of two relays R8 and R9 of the direct current neutral type. The

- shaft I of the commutator C1 is operatively connected with a member the speed of whose movement it is desired to determine through the medium of any suitabledrive mechanism such, for example, as a train of gears not shown. When the apparatus is utilized to control the circuits of a speed control system for railway trains, the shaft I is preferably operatively connected with an axle of the vehicle on which the apparatus is mounted, with the result that the speed of rotation of shaft I is in accordance with the speed of the railway train. A contact brush I0 is rigidly mounted on the shaft I forrotation therewith, and is adapted to engage two annular segments .88 and 69, the arrangement being such nection is broken between the segment -68 and the segment 69 when thebrush-III- stops-in the lower one-half of a revolution: -When the shaft I is rotated, electrical connection is periodically completed between thesegments 69 and 69 during one-half of eachrotation" of brush'lli, the duration which the connection-is completed being dependent upon thespeedof rotation of the shaft -I,-and hence, in turn, dependentupon the speed of the driving member.

The operatingwindings of relays R8 and R9 are connected in series in acontrol circuit including a battery I andthe commutator 01, as will be readily understood by an inspection of the drawing, with the result that current is supplied to these two relays in series during the one-half revolution thebrush I0 engages the segment 69 and the supply of current is discontinued during the one-half revolution the brush IlIis out of engagement with the segment 69. The relay R8 is preferably provided with slow pick-up characteristics and relatively high pick-up characteristics, and the relay R9 is preferably provided with slow release: characteristics and relatively low'pick-up characteristics. "That is to the armature of relay R8 is not raised out of engagement with the back contact I2 until a predetermined timeinterval-subsequent to initiating the energizing of the relay by supplying current to its operating winding (slow pickup characteristics). In the -case 'ofrelay R9, the armature is retained in engagement with the front contact II a predetermined'time period subsequent to termination ofthe supply'of current to the winding of the relay (slow release characteristics). As stated above, the relay R8 is also provided with relatively; high pick-up characteristics. For example, the relay R8 is so proportioned and adjusted that the tractive effort necessary to raise its armature out of engagement with the back contact I2 isproduced when the value of the current flowing in its winding is, say, of the ultimate current value resulting when the control circuit is closed and the battery I is at full" voltage. The relay R9, in addition to being provided with slow release characteristics, is preferably also provided with relatively low pick-up characteristics. That is, the tractive effort necessary to raise its arma- Y ture into engagement with the-front contact II is produced when the current supplied to the winding of relay R9 is, say, only 25% of the ultimate current effected when the control circuit is closed and thefullavoltage .of battery I is obtained. Preferably, the relay R8 would be.

provided with a slow pick-up period substantially equal to the slow release period of relay R9. It will be understood that my invention is not limited to such adjustments of relays R8 and R9, and other adjustments may be used if desired.

The relays R8 and R9 may be utilized to control indication and control devices to determine whether or not the shaft I is moving at all or is moving about or below a predetermined critical speed. As here shown, relays R8 and R9 govern an indication lamp I6 and a control magnet l8 by virtue of a simple circuit which includes the back contact 12 of relay R8 and the front contact "H of relay R9 in series.

At zero speed of shaft l, and with the brush 10 in engagement with segment 69, both relays R8 and R9 are picked up and the indication circuit for the lamp l6 and magnet I8 is open at the back contact '12 of relay R8, with the result that the lamp I6 is dark and the magnet I8 is deenergized. With the brush l0 stopped at the position where it is out of engagement with the segment 69, both relays R8 and R9 are deenergized and the indication circuit is open at front contact H of relay R9. Thus, at zero speed of shaft l the lamp [6 is dark and the magnet I8 is deenergized, irrespective of the position at which the shaft l stops. When the speed of shaft l is such that the brush 1B is rotated at a speed below a predetermined critical speed and the duration of the contact between brush l0 and segment 69 is greater than the pick-up period of therelay R8, the relay R8 is picked up during one-half of each rotation and is released during the other one-half rotation of the brush 10. Under this condition of speed, the duration of the time interval between two consecutive current impulses supplied to the relay R9 is greater than the slow release period of relay R9, and

that relay is released during the one-half rotation the brush T0 is out of engagement with the segment 69. Assuming the shaft I is rotated clockwise at a slow speed, the relays R8 and R9 are both picked up with the brush 'H) in engagement with the segment 69. When the brush it moves off the segment 69, both relays are deenergized and relay R8 releases at once but relay R9 does not release until the end of its slow release period. During the interval between the release of relay R8 and the release of relay R9 the lamp I6 is illuminated. Again, when the brush moves onto the segment 69, both relays are energized and relay R9 is picked up at once but relay R8 is not picked up until the end of its slow pick-up period so that there is an interval when lamp I6 is illuminated. Hence, at speeds between zero and such critical speed, the indication circuit is alternately opened and closed, with the result that the indication lamp i6 is flashed and the control magnet i8 is intermittently energized. At speeds above such critical speed, the duration of the contact between brush l0 and segment 69 is less than the pick-up period of relay R8, and the back contact 12 of relay R8 remains closed. The relay R9, however, is now picked up and its front contact H is closed, since the time interval during which the brush 10 is out of engagement with the segment 69 is less than the slow release period of relay R9. Again, if the speed at which the brush 18 is rotated is relatively high and rapid impulses of current are supplied to the relays R8 and R9 and build up the magnetism in their respective magnetic circuits, the average value of the current flowing in the winding of relay R8 does not reach the 75% pick-up value of current of this relay due to the inductance of the relay and relay R8 remains released. The average value of the current flowing in the winding of relay R9, however, does reach the 25% pick-up value of current of relay R9 and relay R9 is held picked up. Hence, at speeds above the critical speed, the lamp [6 is continuously illuminated and the control magnet I8 is steadily energized.

When apparatus embodying my invention is used in connection with speed control systems for railway trains, the lamp [6 may be used to indicate to the operator on the train the speed above the critical speed, and the magnet l8 may be used to effect a control over the train brake equipment, and when so used an unsafe indication due to a loss of power or breakage of a part is avoided.

Although I have herein shown and described only one form of speed responsive apparatus em.- bodying my invention, it is understood that various changes and modificattions may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. Speed responsive apparatus comprising a shaft adapted to be rotated at diiferent speeds, a commutator mounted on the shaft including a segment of a predetermined length, a brush effective to engage said segment in response to each rotation of the shaft, a first relay provided with a slow pick-up period, a second relay provided with a slow release period, a source of current; a control circuit including the source, the brush, the segment and a winding of each relay in series for energizing the relays a given portion of each rotation of the shaft; and an indication circuit including a back contact of said first relay and a front contact of said second relay in series.

2. Speed responsive apparatus comprising a shaft adapted to be rotated at diiferent speeds, a segment, a brush fixed on said shaft and adapted to engage said segment during substantially one-half of each rotation, a slow pick-up relay, a slow release relay, an indicating device, an operating circuit for said device including a back contact of the slow pick-up relay and a front contact of the slow release relay, a. current source, and means to serially connect the windings of said relays between said segment and one terminal of said source and to connect the other If terminal of the source with said brush for retaining the slow release relay continuously picked up and the slow pick-up relay continuously released tocontinuously display the indicating device only when the shaft is rotated at greater than a speed predetermined by the pick-up and release periods of said relays.

3. Speed responsive apparatus comprising a member adapted to be actuated through an operating cycle at different speeds, circuit controlling contact mechanism operatively connected with said member and including a contact closed during a predetermined portion of each cycle, a slow pick-up relay, a slow release relay, an indicating device, an operating circuit for said device including a back contact of the slow pick-up relay and a front contact of the slow release relay in series, a current source, and a control circuit including the windings of said relays in series and said contact as well as said source for retaining the slow release relay continuously picked up and the slow pick-up relay continuously released to continuously display the indicating device only when said member is actuated at greater than a speed predetermined by the pickup and release periods of said relays.

4. Speed responsive apparatus comprising a member adapted to be actuated through an operating cycle at different speeds, circuit controlling contact mechanism operatively connected with said member and including a contact closed during a predetermined portion of each cycle, a slow pick-up relay, a slow release relay, an indicating device capable of displaying one indication when deenergized and a second indication when ener gized, an operating circuit for said device including a back contact of the slow pick-up relay and a front contact of the slow release relay in series, a current source, and a control circuit serially including the windings of said relays and said contact as well as the current source to cause said device to continuously display said one indication when said member is stationary at any point in its cycle and to cause the device to continuously display the second indication when said member is actuated above a predetermined speed.

5. Speed responsive apparatus comprising a member adapted to be actuated through an operating cycle at different speeds, circuit controlling contact mechanism operatively connected with said member and including a contact closed during a predetermined portion of each cycle, slow acting electromagnetic means provided with a first contact closed only after said means is energized a predetermined time interval and a second contact closed only after said means is deenergized a predetermined time interval, an indicating device, an operating circuit for said indicating device serially including said first and second contacts, a current source, and a control circuit for energizing said electromagnetic means including said source and the contact of said mechanism.

6. Speed responsive apparatus comprising a member adapted to be actuated through an operating cycle at different speeds, circuit controlling contact mechanism operatively connected with said member and including a contact closed during substantially one-half of each cycle, slow acting electroresponsive means provided with a first contact which is closed only after said means is energized a predetermined time interval and a second contact which is closed only after said means is deenergized said predetermined time interval, an indicating device efiective to display a given indication when energized, an operating circuit for said device serially including said first and second contacts, a current source, and a control circuit for said electroresponsive means including said source and the contact of said mechanism to cause the indicating device to continuously display said indication only when said member is actuated at greater than a speed determined by the predetermined time interval of the electroresponsive means.

HERBERT L. BONE. 

